Form roll drive



Oct. 15, 1935. w WOOD 2,017,139

FORM ROLL DRIVE Original Filed Feb 27, 1931 In. lilllllllllllllllllllll int/e Wew/VA .Wcire'fi aad Patented Oct. 15, 1935 UNITED STATES PATENT OFFICE roam non. DRIVE Application February 27, 1931, Serial No. 518,713 Renewed March 6, 1935 7 Claims. (Cl. 101-350) This invention relates to the driving of form rolls in an inking device for a printing press and to a new gear couple. 7

The principal objects of this invention are to provide means for preventing the slipping of the form rollers in such a way as to fill up very fine half tones and the bowls of small type, thus reducing the sharpness of the prints and to provide means whereby when the rubber form rollers increase in size after use and the gears driving them have to be set in loose mesh, the form rollers will be driven positively and yet the gearing will yield sufliciently to compensate for the fact that the gears are not closely in mesh and will drive the form roller positively-after this adjustment of the gears.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing, in which Fig. 1 is a diagrammatic view of a printing couple and inking mechanism showing a preferred embodiment of this invention;

Fig. 2 is a side view of the ink drum and one form roll showing one form of this invention; Fig. 3 is a similar view showing another form; Y Fig. 4 is an end view of the intermeshing gears shown in Fig. 3 in the position when the centers of the rolls are near together, and Fig. 5 is a similar view showing the operation when these gears are separated and in loose mesh. The form rollers 10 of an inking mechanism are made of rubber ordinarily and unless they are set in very tight they are apt to slip or slide. This is due to the fact, apparently, that there is not enough traction between the ink drum and the rubber roller or the plate cylinder and the rubber roller to keep the latter always run ning perfectly at the surface speed of the printing cylinder. This dimculty is accentuated by the frequent necessity of having to change the velocity of the press for paper replenishment and also in starting and stopping the press.

As the form roller is made of India rubber it is elastic. The petroleum, which is a component of newspaper printing ink, affects rubber by gradually swelling or, enlarging it. Therefore the form rollers are always growing larger and, from time to time, they have to be reground to bring them back to their original size. Before this is done, however, their centers have to be moved farther apart to give their surfaces the proper contact. If ordinary gears were used to drive the rollers they would be driven in exact registration with the type only so long half tones and bowls of very small type. It is :3

desired to use gearing or some positive means for driving the form rollers because of the slipping and sliding of their surfaces on the type. The form rollers l0 cooperate with theplate cylinder II and receive ink from the rolls below 10 and from the ink drum l2. The form rollers Ill are mounted in adjustable cap bearings |3 so that they may be moved with respect to the plate cylinder and ink drum in order to give the proper contact pressure. The ink drum has 15 attached to one or both ends of its shaft a wheel M, which is serrated or knurled on its circumferential surface to give it a driving grip on the soft surfaced disc l5 secured to the end of each of the form rollers. These two wheels HI and I5 20 are of course sized correctly, being the same diameter as the two cylinders on which they are located. As the ink drum I2 is driven positively, the wheel I4 is also and it imparts a driving force to the form roll through the disc l5. There- 25 fore that portion of the form roll whose func--- tion it is to supply ink from the ink drum to the plate is relieved of the strain caused by rotating the form r011.

Inthe form shown in Figs. 3, 4 and 5, corre- 30 sponding results are secured in a different way.

On the ink drum I2 is located a gear I! and on the form roll I0 is located a gear 18, one of these gears being metal and the other elastic India rubber. Either one of them may be rub- 35 her but I have shown the one on the form roll as made of that material.

This driving arrangement does not create a hard and fast connection that allows the surface of the form roller to be driven at a speed dif- 40 ferent from that of the surface of the plate. In other words a certain amount of flexibility is allowed to insure good printing. It is not essential that this whole gear be made of rubber or elastic material as merely the teeth may be 45 elastic.

From inspection of Figs. 4 and 5 it will be seen that the second gear will be driven without back-lash when the form rolleris small and the gears are in close mesh as shown in Fig. 4 50 and it will continue to be driven without backlash as the roller l0 grows in diameter and has to be set farther away from the ink drum so that the teeth are in loose mesh as shown in Fig. 5. In either case the elastic teeth .conform 55 to the spaces in which they engage between the teeth of the other gear. This pair of gears not only has thisadvantage but also runs in silence and provides no vibration.

Thus it is evident that means is provided in either form shown, for driving the form rollers in such a way that they may be kept always in harmony with the driving cylinder without'the disadvantage ofa hard and fast drive, which can be detrimental to good printing as has been explained.

Furthermore this pair 'of gears, one rigid and the other flexible, is useful in many other relations and in other arts, wherever it is necessary to change the distance apart of the centers of two gears and secure a surface to surface contact with two cylinders always at the same surface speed.

Although I have illustrated and described only two forms of the invention I am aware of the fact that other modifications can be made therer in by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore I do not wish to be limited in this respect but what I do claim is:-

1. In an inking mechanism, the combination with a form roller and means for driving it having a free driving surface capable of yielding circumferentially to permit the surface of the form roller to move at plate speed when the form roller is set with its axis at different distances from the axis of itsdriving element. i

2. In an inking device, thecombination with the plate cylinder, form rollerand ink drum,

the form roller contacting with both the other members,of means whereby the axis of the form roller may be adjusted to compensate for increase in size, and means for driving the form roller from the ink drum capable of yielding to permit the form roller to rotate at the surface speed of the plate cylinder irrespective of the size of the form roller, and without back-lash.

3. In an; inking mechanism, the combination of a form roller and a rotary member in contact therewith, with a driving device from said rotary member to the form roller comprising a rigid wheel having a serrated surface and a soft surfaced wheel in contact therewith.

4. In an inking device,- the combination with a form roller and a drum in contact therewith, 5

of driving means from the drum to the form roller comprising a pair of gears, one of them made of metal and the other having flexible teeth, for the purpose described.

5. In an inking mechanism, the combination 10 with a form roller and ink drum in contact with which the form roller operates, the form roller being adjustably mounted to compensate for changes in size thereof and the driving means from the ink drum to the form roller compris- 15 ing a pair of intermeshing gears, one of which is of rigid material and the other of which is of flexible rubber to permit the form roller to be driven at the proper surface speed irrespective of, the size and adjustment of the gears in the 20 machine, and without back-lash.

6. In an inking mechanism, the combination of a form roller having a yielding surface fixed with respect to the inking surface thereof and spaced therefrom, with an ink drum having a 25 serrated surface fixed with respect' to the ink carrying surface of the ink drum and spaced therefrom, the form roller and ink drum being in surface contact and the yielding surface and serrated surface cooperating with each other, 30 whereby a driving force may be imparted to the form roller from the ink drum through said surfaces.

'7. In aninking mechanism, the combination of a form roller having a yielding surface fixed with 35 respect thereto, with an ink drum having a serrated surface fixed with respect to the ink drum, the form roller and ink drum being in surface contact and the yielding surface and serrated surface cooperating with each other, said surfaces cooperating on areas of the form roller which do not transmit ink from the form roller, whereby a driving force may be imparted to the form roller from the ink drum.

v HENRY A. WISE WOOD. 

